Faster alternative to nested loops?

Question

I have a need to create a list of combinations of numbers. The numbers are quite small so I can use byte rather than int. However it requires many

Answer 1

Some of your numbers fit entirely on an integer nuimber of bits, so you can "pack" them with the upper level number :

for (byte lm = 0; lm < 12; lm++)
{
    ...
    t[z].l = (lm&12)>>2;
    t[z].m = lm&3;
    ...
}

Of course, this makes the code less readable, but you saved one loop. This can be done each time one of the numbers is a power of two, which is seven time in your case.